Mathématiques

Question

A=9/14-2/7x5
B=8/3-5/3:20/21
C=1-(2/3+1/4)
D=3-5/2/1+1/5

2 Réponse

  • Bonjour


    A  = 9/14 - 2/7 x 5

     A   = 9/14 - 10/7

     A   = 9/14 - 20/14

     A  = -11/14


    B = 8/3 -5/3 : 20/21

    B = 8/3 - 5/3 x 21/20

    B = 8/3 - 105/60

    B = 160/60 - 105/60

    B = 55/60

    B = 11/12


    C = 1 - (2/3 + 1/4)

    C = 1 - (8/12 + 3/12)

    C = 1 - 11/12

    C = 12/12 - 11/12

    C = 1/12

    D = (3-5/2) / (1+1/5)

    D = (6/2 - 5/2) / (5/5 + 1/5)

    D = (1/2) / (6/5)

    D = 1/2 x 5/6

    D = 5/12 



  • A = 9/14 - 2/7 x 5
    A = 9/14 - 10/7
    A = 9/014 - 10 x 2 / 7 x 2
    A = 9/14 - 20/14
    A = - 11/14

    B = 8/3 - 5/3 : 20/21
    B = 8/3 - 5/3 x 21/20
    B = 8/3 - 105/60
    B = 8 x 20 / 3 x 20 - 105/60
    B = 160/60 - 105/60
    B = 55/60
    B = 5 x 11 / 5 x 12
    B = 11/12

    C = 1 - (2/3 + 1/4)
    C = 1 - (2 x 4 / 3 x 4 + 1 x 3 / 4 x 3)
    C = 1 - (8/12 + 3/12)
    C = 1 - 11/12
    C = 1 x 12 / 1 x 12 - 11/12
    C = - 1/12


    D = (3 - 5/2) / (1 + 1/5)
    D = (3 x 2 / 1 x 2 - 5/2) / (1 x 5 / 1 x 5 + 1/5)
    D = (6/2 - 5/2) / (5/5 + 1/5)
    D = (1/2) / (6/5)
    D = 1/2 x 5/6
    D = 5/12


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